A conventional valve assembly is generally used in a pipe system connected to a faucet or a shower head for mixing the cold water and the hot water so that users can get warm water mixed by the hot water and the cold water by operating the lever of the faucet. The conventional valve assembly typically includes a balanced member which is urged at two sides thereof by two springs so that when either one of the hot water or the cold water introduces a high pressure to push the balanced member to an extreme position, the user will be incurred with the hot water with a very high temperature or the cold water with a unexpected low temperature. In order to overcome the spring force so that the water pressure has to be raised to a certain level and this prolongs the reaction time of the valve. That is to say, the conventional valve assembly is not sensitive enough to properly mix the volume of the hot water and the cold water. Furthermore, the springs will reach to their fatigue critical point after a period of time and get rust. This makes the hot water or the cold water entering the valve assembly abnormally and could hurt the users.
The present invention intends to provide a pressure balanced valve assembly which has a proportioning member which is moved relative to the inlets of the hot water and the cold water according to the water pressure applied to the proportioning member. By the valve assembly of the present invention, a proper mixing feature of the hot water and the cold water can be reached so that the inherent disadvantages of the conventional valve assembly can be well mitigated and/or obviated.